Dr Ronald Stiffler SEC technology

[gyulasun]

Gyula,

i checked again with my DC PS, at 20V they draw 60mA, but at 18V it drops to 2.6mA with moderate light.

Yes, i meant the input current measurement  is not possible when i drive the 3 coils by the oscillator.
Probably the RF emitting from the 3 coils is to strong, as even without any cables connected to my analoge
meter it reads 5mA or so (nearby off course).

Itsu

Okay, thanks.  The voltage-current characteristic of the paralleled LED strings within a LED board is very steap to cause the big change in current for the 2 V change in voltage.  But this is normal for LEDs.
I agree, the 3 coil setup surely increases the near field because all the 3 coils are air core coils and nothing confines their EM field like a ferromagnetic core normally does when used. 

[gyulasun]

Hmmm. increased the brightness by paralleling three 13.56 MHz crystal

Hi Erfandl,
I missed to comment your interesting test.  Would you check the DC input current to your oscillator how it changes when the 3 crystals work?

I think the number of oscillator harmonic frequencies are greatly increased with the use of 3 crystals versus a single crystal and this comes at a price of an increased input power too.   The harmonics can only be seen by using a spectrum analyzer (or a selective voltmeter). 
If you find the input current does not increase with the use of 3 crystals, that would be good news...     but I think it increases.
Gyula

[itsu]

Hi Itsu,

Thanks for the comments and measurements,  I appreciate your work very much.
I agree with the schema you show on the 3 coil setup as the Doc introduced it in his video.  Does the trimmer capacitor set to 5 pF give a resonance-like coupling? i.e. can it be adjusted to give a peak brightness and that happens to be around 5 pF? or it has a 'flat' response? Just curious. (I know it is difficult to adjust due to the hand capacitance, perhaps the use of a piece of wood or plastic rod formed to have screwdriver end would reduce hand effects when turning the trimmer with them.)

In the 3 coil setup there are the AV plug diodes inserted between the input coil and the middle coil. This is an unusual connection because the DC resistance of the second coil short circuits the DC component of the rectified RF energy and "only" the RF signals remain to feed the top and bottom ends of the middle coil.  Have you pondered on this DC short?
When you have time next week, could you place the two probes to the ends of the middle coil and use the scope in differential mode to see how the waveforms look like? 

I assume you changed the distance between the input and the middle coil?  Is the distance critical between them in terms of the brightness?

And the most interesting thing is his 1 Ohm voltage drop measurement right at the output of his generator. Have you checked when you remove the 3rd coil with the LED board (as he did) then how the amplitude of the oscillator tank changes? That would be the goal to achieve what he stated: the energy taken out from the generator does not change.

Gyula

Gyula,

the trimmer cap does give a resonance-like coupling,  i use a plactic rod trimmer screwdriver to adjust.


I will take the differential probe measurement on the first AV-plug tonight.
I think we don't need the DC at that middle coil, just the RF AC to excite it.

Changing the distance between the 2 vertical coils has little or no influence on the brightness of the
leds, i demonstrated that in the first video of this setup in post #555.
So it seems that all the RF goes via the AV-plug / links.

Also the 1 Ohm csr measurement with removing the last coil/led strip combo was done in that video around
the 4 minute mark using my FG.

I see little or no change in current then,  but can repeat that for the oscillator circuit.


By the way, now with the trimmer cap set to 5pF and having the leds on using the oscillator i can again
measure the input current using my analoge voltmeter, its still 52mA with the leds at a 17.9V DC level.
(compared to the 2.6mA at 18V for the PS setup).
So the RF is loaded down enough to have no direct influence on the meter.


Thanks,   Itsu

[erfandl]

Hi Erfandl,
I missed to comment your interesting test.  Would you check the DC input current to your oscillator how it changes when the 3 crystals work?

I think the number of oscillator harmonic frequencies are greatly increased with the use of 3 crystals versus a single crystal and this comes at a price of an increased input power too.   The harmonics can only be seen by using a spectrum analyzer (or a selective voltmeter). 
If you find the input current does not increase with the use of 3 crystals, that would be good news...     but I think it increases.
Gyula

Hi Gyula. thanks for reply. I tested and when I use one crystal current is 38 mA when I use three crystal the current is 33.4 mA !  so the brightness increased with lower current 

[NickZ]

   Gyula:   I measured the current on my oscillator. Without the crystal it was 22mA, and with the crystal it was 52mA.   This is with the L3 on a load of 10 leds on an AV plug. This is with an 8v input.
   For some reason, now only the 7.2Mhz crystal is doing anything. No light with the other crystals on. 
Wireless near field distance is only about 1 cm away from the L3, as noticed on the led/av plug.